The present invention relates to a device for the metered dispensing of a fluid from a tubular bag.
Tubular bags are to be understood here as bags which are produced from plastic film and are completely sealed. Such tubular bags are manufactured by machine by means of a corresponding folding of a plastic film, whereupon said bags are completely sealed by means of corresponding welding seams. Such tubular bags then have opening devices which consist substantially of a connection piece comprising a peripheral flange. The flange is welded onto the bag. A cutting element is held in the connection piece so as to be movable in a screwing fashion and can be actuated by means of a screw cap; thus enabling the cutting element, during the initial opening of the screw cap, to move towards the film in a screwing motion and thereby to open the completely closed tubular bag. The advantage of such a tubular bag comprising a corresponding opening device is that the contents of the tubular bag remain completely aseptically packaged and protected until the effective moment of use. Typical examples of such opening devices are known, by way of example, from the Japanese patent application JP 7040982, the WIPO patent application WO 2004/083055 or also from the European patent application EP 1795456, the European patent application 1795456 or the Swiss patent application CH 695019. These tubular bags as well as the opening device thereof are used primarily in the food branch. These closures are particularly prevalent in the area of fruit juices, flavored milk drinks or also other beverage types.
Tubular bags comprising opening devices are, however, also known in which the opening device is designed as a simple screw closure, wherein the closure device is welded between two film edges of the container. Here there are variants in which a cutting device likewise cuts open a film of the tubular bag, as, for example, is known from the European patent application 2143658 or from variants in which the bag remains open per se but the closure has a sealing membrane that is subsequently pierced by a screw cap. Such solutions are described, for example, by the U.S. Pat. No. 6,273,307 or the American patent application US 2008/0073348. Such and similar solutions are typically known for so-called refill bags as they are used, in particular, in the field of cosmetics for liquid soaps, shower gels or hair shampoos. In the case of the refill bags, a permanent receptacle is then filled, wherein the actual closure of that receptacle is unscrewed and removed and screwed on again after the refill procedure.
In the field of gastronomy, substantially larger tubular bags are, however, provided today as refill containers. In particular at fast-food restaurants, viscous, pasty and often thixotropic food products are dispensed from larger containers and are for the most part extracted from said containers using a hand pump. These are today, in particular, large canisters or plastic containers which are provided with a simple screw closure and on which a hand-operated pump is mounted. This has a variety of disadvantages. On the one hand, such containers are seldom aseptically filled and a reusable pump has to be mounted after the initial opening which must be cleaned beforehand. There is also the disadvantage that ambient air enters into the container when removing the screw closure and mounting the corresponding pump. The contents are thus no longer aseptic. In addition, air must be allowed to flow into the container after the pump has been mounted in order to replace the product which has been pressed out; thus allowing a vacuum in the container to be prevented. Because many of such food products used in the field of gastronomy oxidize when coming in contact with the ambient air or otherwise incur damage, said products must consequently be protected from spoiling by the addition of preservatives. This practice is however becoming increasingly unacceptable to consumers.